drm/fb-helper: Push locking into restore_fbdev_mode_atomic|legacy

Same game as with the panning function, use drm_modeset_lock_all for
legacy paths, and a proper acquire ctx w/w mutex dance for atomic.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Thierry Reding <treding@nvidia.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170704151833.17304-8-daniel.vetter@ffwll.ch

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 7c24c8cd2e23cd19dd0825237697616d73978b46..c5bf37f3bcdd6ada5a378b775773b49fedc49697 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -382,12 +382,17 @@ static int restore_fbdev_mode_atomic(struct drm_fb_helper *fb_helper)
        struct drm_atomic_state *state;
        int i, ret;
        unsigned int plane_mask;
+       struct drm_modeset_acquire_ctx ctx;
+
+       drm_modeset_acquire_init(&ctx, 0);
 
        state = drm_atomic_state_alloc(dev);
-       if (!state)
-               return -ENOMEM;
+       if (!state) {
+               ret = -ENOMEM;
+               goto out_ctx;
+       }
 
-       state->acquire_ctx = dev->mode_config.acquire_ctx;
+       state->acquire_ctx = &ctx;
 retry:
        plane_mask = 0;
        drm_for_each_plane(plane, dev) {
@@ -396,7 +401,7 @@ retry:
                plane_state = drm_atomic_get_plane_state(state, plane);
                if (IS_ERR(plane_state)) {
                        ret = PTR_ERR(plane_state);
-                       goto fail;
+                       goto out_state;
                }
 
                plane_state->rotation = DRM_MODE_ROTATE_0;
@@ -410,7 +415,7 @@ retry:
 
                ret = __drm_atomic_helper_disable_plane(plane, plane_state);
                if (ret != 0)
-                       goto fail;
+                       goto out_state;
        }
 
        for (i = 0; i < fb_helper->crtc_count; i++) {
@@ -418,23 +423,27 @@ retry:
 
                ret = __drm_atomic_helper_set_config(mode_set, state);
                if (ret != 0)
-                       goto fail;
+                       goto out_state;
        }
 
        ret = drm_atomic_commit(state);
 
-fail:
+out_state:
        drm_atomic_clean_old_fb(dev, plane_mask, ret);
 
        if (ret == -EDEADLK)
                goto backoff;
 
        drm_atomic_state_put(state);
+out_ctx:
+       drm_modeset_drop_locks(&ctx);
+       drm_modeset_acquire_fini(&ctx);
+
        return ret;
 
 backoff:
        drm_atomic_state_clear(state);
-       drm_atomic_legacy_backoff(state);
+       drm_modeset_backoff(&ctx);
 
        goto retry;
 }
@@ -443,8 +452,9 @@ static int restore_fbdev_mode_legacy(struct drm_fb_helper *fb_helper)
 {
        struct drm_device *dev = fb_helper->dev;
        struct drm_plane *plane;
-       int i;
+       int i, ret = 0;
 
+       drm_modeset_lock_all(fb_helper->dev);
        drm_for_each_plane(plane, dev) {
                if (plane->type != DRM_PLANE_TYPE_PRIMARY)
                        drm_plane_force_disable(plane);
@@ -458,32 +468,31 @@ static int restore_fbdev_mode_legacy(struct drm_fb_helper *fb_helper)
        for (i = 0; i < fb_helper->crtc_count; i++) {
                struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
                struct drm_crtc *crtc = mode_set->crtc;
-               int ret;
 
                if (crtc->funcs->cursor_set2) {
                        ret = crtc->funcs->cursor_set2(crtc, NULL, 0, 0, 0, 0, 0);
                        if (ret)
-                               return ret;
+                               goto out;
                } else if (crtc->funcs->cursor_set) {
                        ret = crtc->funcs->cursor_set(crtc, NULL, 0, 0, 0);
                        if (ret)
-                               return ret;
+                               goto out;
                }
 
                ret = drm_mode_set_config_internal(mode_set);
                if (ret)
-                       return ret;
+                       goto out;
        }
+out:
+       drm_modeset_unlock_all(fb_helper->dev);
 
-       return 0;
+       return ret;
 }
 
 static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 {
        struct drm_device *dev = fb_helper->dev;
 
-       drm_warn_on_modeset_not_all_locked(dev);
-
        if (drm_drv_uses_atomic_modeset(dev))
                return restore_fbdev_mode_atomic(fb_helper);
        else
@@ -503,7 +512,6 @@ static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
  */
 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
 {
-       struct drm_device *dev = fb_helper->dev;
        bool do_delayed;
        int ret;
 
@@ -511,15 +519,11 @@ int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
                return -ENODEV;
 
        mutex_lock(&fb_helper->lock);
-       drm_modeset_lock_all(dev);
-
        ret = restore_fbdev_mode(fb_helper);
 
        do_delayed = fb_helper->delayed_hotplug;
        if (do_delayed)
                fb_helper->delayed_hotplug = false;
-
-       drm_modeset_unlock_all(dev);
        mutex_unlock(&fb_helper->lock);
 
        if (do_delayed)
@@ -577,11 +581,9 @@ static bool drm_fb_helper_force_kernel_mode(void)
                        continue;
 
                mutex_lock(&helper->lock);
-               drm_modeset_lock_all(dev);
                ret = restore_fbdev_mode(helper);
                if (ret)
                        error = true;
-               drm_modeset_unlock_all(dev);
                mutex_unlock(&helper->lock);
        }
        return error;